JP2000211556A - Working vehicle with cab which can move up and down - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working vehicle provided with a cab which can move up and down by attaining compactness of the vehicle while improving working visibility by making the cab movable toward the front side upwardly in the slanting direction, and a working vehicle of which a manufacturing cost can be reduced by using a standard specification vehicle and making the cab movable up and down. SOLUTION: A lifting mechanism 4 with a four joint parallel linkage structure was composed by connecting a frame 2 side of a vehicular body 1 and a bottom side of a cab 3 through a pair of linkage member 7, 8. Each linkage member 7, 8 is composed such that cab side pivotally mounting parts 9, 10 are positioned behind frame side pivotally mounting parts 11, 12 when the cab 3 is in a lowering position, and a hydraulic cylinder is provided in order to move the cab 3 toward the front upwardly in the slanting direction by forward rotation of each linkage member 7, 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working vehicle such as a hydraulic excavator having a cab that can be raised and lowered.

[0002]

2. Description of the Related Art In a working vehicle such as a hydraulic excavator, it is known that a cab can be raised and lowered in order to improve the working visibility (for example, Japanese Patent Application Laid-Open No. 8-326101, Japanese Utility Model Application Laid-Open No. 60-193873, JP-A-10-886
No. 18). Of these, Japanese Patent Application Laid-Open No. 8-326101 discloses a method in which the cab is simply raised and lowered with respect to the vehicle body in a vertical direction, and a sufficient visibility improving effect cannot be obtained. No. and JP-A-Hei 1
Japanese Patent Publication No. 0-88618 discloses that the cab can be moved not only upward but also forward to improve the working visibility. That is, in the latter, a support is erected on the vehicle body at the rear position of the cab, a four-bar parallel link is formed between the support and the back of the cab, and the cab is moved forward by moving the four-bar parallel link. It can be moved diagonally upward.

[0003]

By the way, in the above-mentioned conventional working vehicle, a pillar is erected on the vehicle body at a position rearward of the cab, and a support is provided between the pillar and the rear face of the cab.
By providing the node parallel links, a cab elevating mechanism is configured. Therefore, in the above-mentioned conventional device, an extra arrangement space is required in the front-rear direction of the vehicle in order to arrange the cab elevating mechanism. For this reason, there is a disadvantage that the vehicle cannot be made compact, and because of the extra layout space, the standard specification vehicle cannot be used as it is, and the vehicle that can raise and lower the cab must be a special specification vehicle. I can't get it.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and an object of the present invention is to improve the work field of view by making the cab movable diagonally forward and upward, while maintaining the conventional cab. Another object of the present invention is to provide a working vehicle equipped with a vertically movable cab that does not require an extra space in the front-rear direction of the vehicle. It is also an object of the present invention to provide a working vehicle capable of raising and lowering the cab using a standard specification vehicle as it is, thereby reducing the manufacturing cost.

[0005]

Means and Effects for Solving the Problems Claim 1
The working vehicle provided with a cab that can be moved up and down is provided with a cab 3 in front of the vehicle body 1 and the gantry 2 side of the vehicle body 1 and the bottom surface side of the cab 3 are connected by a pair of link members 7 and 8. Constitutes a lifting mechanism 4 having a four-section parallel link structure, whereby the cab 3 can be raised and lowered.
Each of the link members 7 and 8 is configured such that when the cab 3 is at the lowered position, the cab-side pivot portions 9 and 10 are located behind the gantry-side pivot portions 11 and 12. By rotating the cabs 7 and 8 forward, the cab 3
Hydraulic cylinder 1 for moving the cylinder obliquely upward and forward
4 is provided.

According to the working vehicle provided with the cab that can be raised and lowered according to the first aspect, the cab 3 is moved by rotating the link members 7 and 8 forward by extending the hydraulic cylinder 14. It is possible to improve the working field of view by moving the front obliquely upward. Since the elevating mechanism 4 for that purpose is arranged between the gantry 2 and the bottom surface of the cab 3, no extra arrangement space is required in the front-rear direction of the vehicle body 1 as in the prior art, so that the entire working vehicle is compact. Configurable.

According to a second aspect of the present invention, there is provided a working vehicle having a cab that can be moved up and down, wherein the cab 3 can be directly attached to the gantry 2, while the cab 3 is provided between the gantry 2 of the vehicle body 1 and the cab 3. A lifting mechanism 4 comprising a base 5 and a platform 6 and a pair of link members 7, 8 and a hydraulic cylinder 14 disposed between the base 5 and the platform 6; The platform 6 is provided with a cab 3 mounting structure similar to the gantry 2,
Further, the base 5 is provided with a mounting structure to the gantry 2 similar to the cab 3.

According to the working vehicle having the cab that can be raised and lowered according to the second aspect of the present invention, when it is not necessary to provide the raising and lowering mechanism 4, the cab 3 may be directly attached to the gantry 2. When the mechanism 4 needs to be provided, the lifting mechanism 4 may be provided between the gantry 2 and the cab 3. In other words, a standard specification that does not require the provision of the lifting mechanism 4 is used as it is, and if the lifting mechanism 4 is added thereto, it is possible to change to the lifting cab specification by itself.
As a result, manufacturing costs can be reduced.

According to a third aspect of the present invention, there is provided a working vehicle having a vertically movable cab, wherein the link members 7 and 8 are provided on the left and right sides of the cab 3, respectively, and the base end of the hydraulic cylinder 14 is attached to the gantry 2 side. The distal end is attached further forward than the pivots 9, 10 of the link members 7, 8 on the cab 3 side.

According to the working vehicle having the cab that can be raised and lowered according to the third aspect, the cab 3 is supported by the hydraulic cylinder 14 on the front side in addition to the left and right link members 7 and 8. Will be. That is, the cab 3 is supported at five points by these, and as a result, the cab 3 is in the up-down operation and in the up state.
Stability can be ensured.

According to a fourth aspect of the present invention, there is provided a working vehicle having a cab which can be moved up and down, provided with a stopper for regulating the forward rotation of each of the link members 7 and 8 so as not to exceed the top dead center of the link trajectory. It is characterized by:

According to the working vehicle having the cab that can be raised and lowered according to the fourth aspect of the present invention, it is possible to ensure the safety of the lifting operation.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a working vehicle equipped with a liftable cab according to an embodiment of the present invention. First, FIG. 1 shows a schematic configuration of an entire working vehicle such as a hydraulic shovel. In FIG. 1, reference numeral 1 denotes a vehicle main body.
The gantry 2 is pivotably supported on the upper part. A cab (operating cab) 3 is mounted via an elevating mechanism 4 at a position on the upper side of the gantry 2 and on one side in front of the vehicle body 1. The elevating mechanism 4 includes a base 5 mounted on the gantry 2, and a platform 6 supported by the base 5 so as to be able to move up and down and on which the cab 3 is placed.

In the elevating mechanism 4, the base 5
And the platform 6 are connected by a pair of link members 7 and 8, thereby forming a four-node parallel link. When the cab 3 is at the lowered position as shown in FIG. 1, the link members 7 and 8 are connected to the pivot portions 9 and 10 of the link members 7 and 8 on the platform 6 side. It is arranged so as to be located on the rear side of the vehicle with respect to 11 and 12. That is, the pivot portions 11 and 12 on the base 5 side are provided at the front portion and the center portion of the base 5, and the pivot portions 9 and 10 at the platform 6 side are provided at the center portion and the rear portion of the platform 6. It is. As shown in FIG. 3, the link members 7 and 8 are respectively provided on the left and right sides of the vehicle body 2, and the link members 7 and 8 on both right and left sides are connected by a connecting member 13. It is in the shape of a shape. A hydraulic cylinder 14 is disposed between the left and right link members 7 and 8. The cylinder side of the hydraulic cylinder 14 is connected to the base 5, and the rod side thereof is connected to the platform 6. The connecting position of the rod to the platform 6 in the hydraulic cylinder 14 is set at the front end thereof, whereby the platform 6, that is, the cab 3 is moved by the right and left link members 7 and 8 in the central and rear portions thereof. point,
And the hydraulic cylinder 14 supports a total of five points, one at the center of the front end.

The cab 3 can be directly attached to the gantry 2. That is, as shown in FIG. 4, assuming a standard vehicle in which the cab 3 is directly attached to the gantry 2, if the elevating mechanism 4 is interposed between the gantry 2 and the cab 3, the cab 3 can be used as it is. It can be changed to. Therefore, the mounting structure of the cab 3 is provided on the upper surface of the platform 6 in the elevating mechanism 4, and the mounting structure of the cab 2 is completely similar to the bottom plate 20 of the cab 3 on the lower surface of the base 5. A mounting structure is provided.

FIG. 5 shows an example of a structure for attaching the cab 3 to the gantry 2. As shown in the figure, a bottom plate 20 is attached to the bottom of the cab 3, and this bottom plate 20 is attached to the gantry 2 at four corners thereof through viscous mounts 21 and 21. It is mounted via mounts 22. Reference numeral 23 denotes a nut, 24 denotes a washer, 25 denotes a detent bolt, and 26 denotes a spacer. The mounting structure of the cab 3 on the upper surface of the platform 6 is
The mounting structure of the lower surface of the base 5 to the gantry 2 is exactly the same as that of the cab 3. The viscous mount 21 is for reducing the vibration of the cab 3 and is provided with a vibration absorbing rubber and a vibration absorbing structure in which silicone oil is sealed with the rubber to improve ride comfort, reduce operator fatigue, improve work efficiency, and improve cab efficiency. The third is to improve the reliability and durability.

FIG. 6 shows a hydraulic circuit for driving the hydraulic cylinder 14. In the figure, 30 is an engine, 31 and 31 are main pumps, 32 is a charge pump, 33 is a main valve, 34 is a service valve, 3
5 is a pedal, 36 is a PPC valve (pilot pressure control valve), 37 is a lock valve, and 38 is a tank. Now, when the operator enters the cab 3 and starts up the vehicle main body 1 with the starting device in the room, and then the operator steps forward on the pedal 35 in the cab 3, the pressure oil Pi is discharged from the charge pump 32 in the vehicle main body 1. P
It flows to the PC valve 36 and flows to the service valve 34 as pilot pressure oil Pib. And service valve 34
At the end of the main pump 31
Pressure oil PA to the actuator circuit B of the service valve 34
To supply. On the other hand, the lock valve 37 of the actuator circuit B receives the pilot pressure oil Pib of the PPC valve 36, and the pressure oil PA of the actuator circuit B
Open the lock so that it flows to the bottom of the The pressure oil PA flowing into the bottom of the hydraulic cylinder 14 raises the lifting mechanism 4 by extending the cylinder rod, and moves the cab 3 obliquely upward and forward. When the depression of the pedal 35 of the PPC valve 36 is stopped and the PPC valve 36 is positioned at the neutral position,
The circuit of the pilot pressure oil Pib is closed, the lock valve 37 automatically closes the actuator circuit B,
The bottom circuit holding pressure of the hydraulic cylinder 14 is held. Conversely, when the operator steps on the pedal 35 in the cab 3 backward, the lifting mechanism 4 is lowered by the reverse operation, and the cab 3 returns to the lowered position.

As described above, according to the working vehicle, FIG.
When the hydraulic cylinder 14 is extended from the state shown in FIG. 2, the four-node parallel link of the lifting mechanism 4 rotates forward along the arc-shaped link trajectory to near its top dead center, as shown in FIGS. 2 and 3. The cab 3 can be moved obliquely upward on the front side, so that the working field of view can be improved. Although not shown, it is preferable to provide a stopper for restricting the forward rotation of each of the link members 7 and 8 from exceeding the top dead center of the link trajectory. If such a stopper is provided, Safety in the elevating operation can be secured. In the working vehicle described above, the lifting mechanism 4 is disposed between the gantry 2 and the bottom surface of the cab 3, and therefore does not require an extra arrangement space in the front-rear direction of the vehicle body 1 as in the related art. The entire working vehicle can be made compact. Further, according to the working vehicle, the cab 3 may be directly attached to the gantry 2 when the elevating mechanism 4 is not required, or the cab 3 is required when the elevating mechanism 4 is required. An elevating mechanism 4 may be interposed between the cab 2 and the cab 3.
In other words, the standard specification that does not require the provision of the lifting mechanism 4 can be used as it is, and if the lifting mechanism 4 is added thereto, it is possible to change to the lifting cab specification by itself, thereby reducing the manufacturing cost. It becomes possible. Further, according to the working vehicle, the cab 3 is supported by the hydraulic cylinder 14 on the front side in addition to the left and right link members 7 and 8. In other words, the cab 3 is supported at five points by these, and as a result, the stability of the cab 3 during the elevating operation and the ascending state can be ensured.

The specific embodiment of the working vehicle provided with the cab that can be raised and lowered according to the present invention has been described above.
The working vehicle provided with the cab that can be raised and lowered according to the present invention is not limited to the above embodiment, and can be implemented with various modifications. For example, in the above description, the lifting mechanism 4 is
Although a unit structure that is detachable between the cab 3 and the cab 3 is shown, a structure in which the link members 7 and 8 and the hydraulic cylinder 14 are directly connected to the gantry 2 and the cab 3 may be employed. The mounting structure of the gantry 2 and the base 5 and the mounting structure of the platform 6 and the cab 3 can be variously changed and implemented. Furthermore, in the above description, a hydraulic excavator is illustrated as a working vehicle, but this may be a working vehicle having other functions.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a state in which a cab is lowered in an embodiment of a work vehicle including a cab that can be raised and lowered according to the present invention.

FIG. 2 is a schematic side view showing a state in which a cab is raised in the embodiment.

FIG. 3 is a schematic front view of the above embodiment in an ascended state shown in FIG. 2;

FIG. 4 is a schematic side view for explaining compatibility between a standard specification and a lift cab specification in the embodiment.

FIG. 5 is an exploded perspective view for explaining a mounting state of a cab to a gantry in the embodiment.

FIG. 6 is a hydraulic circuit diagram of an embodiment of a working vehicle provided with the cab that can be raised and lowered.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle main body 2 Base 3 Cab 4 Elevating mechanism 5 Base 6 Platform 7 Link member 8 Link member 9 Pivot part 10 Pivot part 11 Pivot part 12 Pivot part 14 Hydraulic cylinder

Claims (4)

[Claims] 1. A cab (3) in front of a vehicle body (1).
And a cab (3) and a gantry (2) side of a vehicle body (1).
The work vehicle has a four-node parallel link elevating mechanism (4) constructed by connecting the bottom side of the vehicle with a pair of link members (7) (8), thereby enabling the cab (3) to move up and down. Therefore, in each of the link members (7) and (8),
When the cab (3) is in the lowered position, the cab-side pivots (9) and (10) are configured to be located behind the gantry-side pivots (11) and (12), and the link members (7 )
A working vehicle equipped with a cab that can be moved up and down, characterized in that a hydraulic cylinder (14) is provided for moving the cab (3) obliquely upward and forward by the forward rotation of (8). 2. The vehicle body (1), wherein the cab (3) can be directly attached to the gantry (2).
A base (5) and a platform (6) are provided between the base (2) and the cab (3), and the pair of link members are provided between the base (5) and the platform (6). (7) A lifting mechanism (4) including a hydraulic cylinder (14) and a hydraulic cylinder (14) is provided, and a cab (3) mounting structure similar to the gantry (2) is mounted on the platform (6). 2. The working vehicle according to claim 1, wherein the base (5) is provided with a mounting structure to the gantry (2) similar to the cab (3). 3. The link members (7) and (8) are provided on the left and right sides of the cab (3), respectively, and the base end of the hydraulic cylinder (14) is attached to the gantry (2), and the distal end thereof Are the two link members (7) on the cab (3) side.
The working vehicle provided with a cab that can be raised and lowered according to claim 1 or 2, wherein the working vehicle is mounted further forward than the pivot portion (9) (10) of (8). 4. A stopper for restricting a forward rotation of each of the link members (7) and (8) from exceeding a top dead center of a link trajectory. Item 6. A work vehicle comprising the cab that can be raised and lowered according to any one of Items 3.